The largest uncertainty in the present calculations arises from the choice of the potential
\(V(r)\)  for the atomic electron, and the consequent form of the radial functions \(g(r)\)  and
\(f(r)\)  used in the evaluation of the radial matrix elements (REF ). The choice of a
Coulombic potential with an effective nuclear charge \(Z_{\mathrm {eff}}=Z-s_{i}\)  to account
for electron screening effects is convenient
and should be accurate for the small values of \(n\)  and \(n-l\)  occurring in the ground states
of neon and argon [1]}. However, if increased accuracy is required, or extension to,
for example, xenon is considered, then self-consistent relativistic radial
eigenfunctions [2]}, [3]} would be needed.
